Method of making brake drums



April 4,1939. D-.'IJ. CAMPBELL 2,153,173-

' METHOD OF MAKING BRAKE DRUMS Original Filed Oct. 12, 1956 s she ts-sheet 1 IN VE N TOR A rromw: y

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Y B u 5 Sheets-Sheet 3 D. J. CAMPBELL METHOD OF MAKING BRAKE DRUMS ori inal Filed Oct, 12, 1936 April 4, 1939.

ATTORNEY Patented Apr. 4, 1939 METHOD OF MAKING BRAKE mums Donald J. Campbell, Spring Wyant &

Heights, Mich.,' a corpoor to Campbell,

Comp ny, Muskegon ration of Michigan Original application 105,293. Divided 2'1, 1937, Serial No.

ber 'I;1938

Lake, Mich assign- Cannon Foundry October 12, '1936, Serial No. and this application July 155,889. Renewed Novem- Claims. on. sir-152,2)

This is a divisional application taken from application, Serial No. 105,293, flied October 12, 1936, by applicant and includes the same description, like drawings and method claims submitted therewith, and

My present invention relates to improvements in brake drums and particularly to an improved method 'of making brake drums of" composite structure whereof a braking into andjusedto a supporting shell-of steel and to a heat transfer member located withinthe shell; and the'principal objects of improvement are to provide a composite brake drum having inherent means for increasing the heat transfer from the cast metal of the braking band to the steel supporting shell; to provide a composite brake drum in which the heat generated by friction caused by the application of the braking shoes will be more rapid than heretofore, and to provide a composite brake drum having the above said objects cheaply. These objects and others not specifically enumerated are attained and will be apparent from a perusal of the following description when taken in connection drawings, in which:

Figure -1 is a side brake drum. I

Figure 2 is a sectional view of the double width steel supporting shell of the brake drum.

elevation of my composite Figure 31s a side view of one of the heat transfer inserts employed.-

Figure 4 is a sectional view of a double width supporting shell having the heat transfer inserts in position within the annular corrugations of" the supporting shell and illustrating the corrugations bending rollers in position as when starting to close the corrugations onto the heat transferinsert. I

Figure 5 is a sectional view as of Figure 4 illustrating the corrugations closed against the heat transfer insert by the corrugation bending rollers.

Figure 6 illustrates in section the double width brake drum supporting shell as during the operation of lining the same with molten metal.

Figure '7 is a sectional view of a portion of a completed. composite brake drum of my preferred structure; "illustrating the heat transfer insert after it has been melted by the molten metal and I again solidified.

Figure 8 is a sectional view of a modified strum ture as of Figure '7 except therein the heat transfer insert has been cut and portions thereof bent against the inner periphery of the supporting ,shell. a

band of metal is cast with the accompanying Throughout the several views of the drawings. to similar parts, and resimilar numbers refer ferring thereto:

[represents the steel supporting shell from which, after it is lined, is cut as by severing circumferentially intermediate its ends two composite brake drums as illustrated by the fragmentary views shown in Figs. 7 and 8, consisting of the steel shell I having at one of its sides inwardly extending annular flange 2, axially extended flange portion hollow annular corrugatidns 4 in which are located heat transfer inserts S'preferably of cop r or ofother non-ferrous metal having a hig er heat conduction factor than the steel of the supportingshell and that of the cast metal lining 6, which is machined at its radial side I to conform to suitable sealing means and at its inner periphery 8 to the required diameter for receiving any suitable braking shoes and mechanism and also to provide a smooth braking surface.

In Fig. 6 is illustrated a double widthsteel shell in the process of lining with molten metal, 9 representing a pouring box or ladle fromwhich is being poured the 'molten metal III to form. when cooled, the lining or braking band 6. During the process of lining, the steel shell is preferably heated to a temperature that will prevent chilling of the moltenmetal as it is poured into the steel supporting shell which is then revolved while held concentric with the axis of rotation by taper chuck jaws l i slidable in the conical bore of outer collet chuck member H by spider l3 secured to slldable shaft It and also by annular head l6 secured to slidable shaft it.

In Fig. 4 is shown roller il pressing against the inner periphery of the supporting shell i and adjustable roller It in contact with the outer wall surface of the corrugations t as the operation of bending thewalls' of the corrugations to press the walls in against the heat transfer inserts 5 is be gun. It represents clearance between the roller H and the inward radially extending flange 2 of the shell i, whereby as the corrugation walls are bent against the heat transfer inserts 5, the said flange 2 is permitted to move toward the roller i7 freely. In Fig. 5 the clearance iii is less because the roller it'has pressed the walls of the corrugations tightly against the sides of the heat transfer inserts and the'ilange 2 has consequently been drawn towards the roller ll.

In the production of my present improved composite brake drum, I first provide the double width supporting shell i as by forming from sheet steel; with an inward radially extending flanges 2 with a centrally located enlarged diameter to form thicker or heavier portion adjacent the axially extended flange 3, and outwardly eX- tending annular corrugations l in theform shown in Fig. 4 with their opposite sides flaring or in inclined relation to each other. I then insert the circular heat transfer inserts 5 which are'each composed preferably of a split copper ring So as shown in Fig. 3, split as indicatedat 5b to allow the ring to be sprung in order that it may be placed within the groove of the annular corrugation 4 and roll or otherwise press the sides of the annular corrugations 4 securely against the opposite sides of the heat transfer insert 5 as shown in Fig. 5, after which the steel supporting shell is placed in a suitable spinning machine where the supporting shell is revolvedrapidly and molten metal, such as iron having a sufficiently high temperature to produce a plastic film on the inner periphery of the steel supporting shell and to melt thetransfer member,

is deposited within the rotating steel supporting shell and fused thereto, causing the heat transfer insert to be fused tothe walls of the annular groove of the annular corrugations and to the 'metal lining 6.

I claim:

1. The method of making brake drums which comprises providing a cylindrical steel shell having between its ends a plurality of outwardly 3,153,173 flange 2 at each of its ends and intermediate the extending annular corrugations, locating in said corrugations heat transfer members, bending the side walls of said corrugations against the sides of said heat transfer members, revolving the said steel shell and heat transfer inserts and while the shell is revolving, casting into the said shell and onto the said heat transfer members a metal lining, cooling the said shell, lining and-inserts, severing the shell and lining circumferentially into a plurality of brake drum portions.

2. The method of making brake drums which comprises providing a cylindrical steel shell having at one of its ends an inward, substantially radially'extending flange, and intermediate its ends an outwardly extending hollow annular corrugation, locating in the hollow of said corrugation a heat transfer insert member, bending the walls of said corrugation against the said insert, revolving the said shell and-insert and while revolving, casting onto said insert a metal braking band member.

3. The method of making brake drums which includes the acts of providing a cylindrical shell having intermediate its ends an outwardly extending corrugation, locating in said corrugation a. heat transfer member, pressing the walls of the corrugation against the heat transfer memher and castingonto the heat transfer member a lining for the said shell.

J. CAMPBELL. 

